1,3-disubstituted-2-trichloromethyl-5-imino-1,3-imidazolidinones as herbicides

ABSTRACT

Compound of the formula   WHEREIN Y is oxygen or sulfur, R1 is alkyl of 1 to 8 carbon atoms substituted with 0 to 3 halogen atoms or aryl of 6 to 10 carbon atoms substituted with 0 to 3 halogen atoms, R2 is hydrogen, R1, an alkoxy of 1 to 8 carbon atoms or phenoxymethyl substituted with 0 to 3 halogen atoms in the benzene nucleus. The compounds are pesticides and/or herbicides.

United States Patent [19] Singer [451 Mar. 12, 1974.

l l 1,3-DISUBSTITUTED-2- TRICI-ILOROMETHYL-S-IMINO-I,3- IMIDAZOLIDINONES AS HERBICIDES [75] Inventor: Malcolm Scott Singer, Richmond,

Calif.

[73] Assignee: Chevron Research Company, San

Francisco, Calif.

[22] Filed: Aug. 21, 1972 [21] Appl. No.: 282,514

Related US. Application Data [62] Division of Ser. No. 69,466, Sept. 3, 1970, Pat. No.

FOREIGN PATENTS OR APPLICATIONS 8,598 4/1969 Japan 71/92 4/1969" Japan 71/ 12 3/1961 Canada 71/92 Primary Examiner-Glennon H. Hollrah Attorney, Agent, or Firm-G. F. Magdeburger; J. Ston er, Jr.; Raymond Owyang [57] ABSTRACT Compound of the formula wherein Y is oxygen or sulfur, R is alkyl of 1 to 8 carbon atoms substituted with O to 3 halogen atoms or aryl of 6 to 10 carbon atoms substituted with 0 to 3 halogen atoms, R is hydrogen, R, an alkoxy of 1 to 8 carbon atoms or phenoxymethyl substituted with 0 to 3 halogen atoms in the benzene nucleus. The compounds are pesticides and/or herbicides.

8 Claims, No Drawings BACKGROUND OF THE INVENTION 1. Field The subject invention is directed to l,3-disubstituted- 2-trichloromethyl-5-imino-1 ,3-imidazolidinones and their 4-thio analogs, which find use as herbicides, pesticides, e.g., fungicides and nematocides.

2. Description of the 111121111611 The compounds of the-present invention can be I represented by the formula wherein Y is oxygen or sulfur, R is alkyl of 1 to 8 carbon atoms substituted with to 3 halogen atoms of atomic number 9 to 35 (fluorine, chlorine or bromine), aryl of 6 to carbon atoms substituted with O to 3 halogen atoms of atomic number 9 to 35, R is hydrogen, R (i.e., alkyl of l to 8 carbon atoms substituted with 0 to 3 halogen atoms of atomic number 9 to 35 or aryl or 6 to 10 carbon atoms substituted with O to 3 halogen atoms of atomic number 9 to 35), an alkoxy of 1 to 8 carbon atoms, or phenoxyalkyl the alkyl group having 1 to 4 carbon atoms, substituted with O to 3 halogen atoms on the benzene nucleus.

Preferably R is alkyl of l to 4 carbon atoms, alkyl of 1 to 4 carbon atoms substituted with l to 3 halogen atoms of atomic number 9 to 35, phenyl, phenyl substi-' tuted with l to 3 halogen atoms of atomic number 9 to 35, R is hydrogen, alkyl of l to 4 carbon atoms, alkyl of l to 4 carbon atoms substituted with 1 to 3 halogen atoms of atomic number 9 to 35, phenyl, phenyl substituted with l to 3 halogen atoms of atomic number 9 to 35, alkoxy of l to 4 carbon atoms, phenoxymethyl or of l to 4 carbon atoms or phenyl, R? is hydrogen, alkyl' of l to 4 carbon atoms, alkyl of l -butylphenyl, to 4 car bon atoms substituted with l to 3 halogen atoms of atomic number 17 to 35, phenyl, phenylsubstituted with l to 3 halogen atoms of atomic number 17 to 35, or phenoxymethyl substituted with l to 2 halogen atoms of atomic number 17 to 35 on the benzene nucleus.

Preferably the halogen substituents for R and R will phenyl-4-thio-5-imino-l ,3-imidazolidinone,

2 chlorophenyl, p-chlorophenyl, m-bromo'phenyl, 0- chloro-p-bromophenyl.

Representative radicals which R can represent include in addition to those listed for R, hydrogen, phenoxymethyl, phenoxyethyl, phenoxypropyl, phenoxybutyl, o-chlorophenoxymethyl, p-chlorophenoxymethy], 0,p-dichlorophenoxymethyl, methoxy, ethoxy, isopropoxy, butoxy, hexoxy, octoxy, etc.

Representative compounds of the present invention include 1-formyl-2-trichloromethyl3-phenyl-5-iminol ,3-imidazolidinone, l-formyl-2-trichloromethyl-3 I-formyl- 2-trichloromethyl-3-methyl-5-imino-l ,3- imidazolidinone, l-formyl-2-trichloromethyl-3 -0- chlorophenyl-S-iminol',3-imidazolidinone, l-acetyl-Z- trichloromethyl-3-methyl-5-imino-l ,3- imidazolidinone, l-acetyl-2-trichloromethyl-3-n-butyl- 5-iminol ,3-imidazolidinone, l-acetyl-2- trichloromethyl-3-phenyl-5-imino-l ,3- I imidazolidinone, 1-acetyl-2-trichloromethyl-3 -pbutylphenyl-4-thio-5-imino-l ,3-imidazolidinone, lpropionyl-Z-trichloromethyl-3-phenyl-5-iminol ,3- imidazolidinone, 1-butyryl-2-trichloromethyl-3- phenyl-5-iminol ,3-imidazolidinone, 1-pentanoyl-2- trichloromethyl-3-0,p-dichlorophenyl-4-thio-S-iminol ,3-imidazolidinone, l-hexanoyl-2-trichloromethyl-3- phenyl-S-imino-l ,3-imid'azolidinone, l-octanoyl-Z- trichloromethyl-3-tolyl-4-thio-5-imino-1 ,3- imidazolidinone, 1-( 2-chloroacetyl) 2-trichloromethyl- 3-hexyl-5-imino-l ,3-imidazolidinone, 1-( 2- bromoacetyl )-2-trichloromethyl-3-phenyl-5-imino-l ,3- imidazolidinone, l-(3-chloropropionyl) -2- trichloromethyl-3-p-fluorophenyl-4-thio 5-imino- 1 ,3- imidazolidinone, l-benzoyl-2-trichloromethyl-3- phenyl-S-imino-l ,3-imidazolidinone, 1-benzoyl-2-trichloromethyl-3-n-butyl-5-iminol ,3-imidazolidinone, 1-benzoyl-2-trichloromethyl-3- phenyl-'4ethio-5-iminol ,3-imidazolidinone, 1-(0- chlorobenzoyl)-2-trichloromethyl-3-ethyl-5-imino-l ,3- imidazolidinone, l-phenoxyacetyl-2-trichloromethyl-3- methyl-5-imino-l ,3-imidazolidinone, 1 phenoxypropenyl-Z-trichloromethyl-3-ethyl-4-thio-5- imino- 1 ,3-imi'dazolidinone, l-( 2- chlorophenoxyacetyl)-2-trichloromethyl-3-methyl-5- imino-l ,3-imidazolidinone, l-( 3- chlorophenoxyacetyl)-2-trichloromethyl-3-phenyl-5- imino-l ,3-imidazolidinone, l-( 2,4- dichlorophenoxyacetyl)-2-trichloromethyl-3methyl-4- thio-S-imino-I ,3-imidazolidinone, 1-(2,4,6- trichlorophenoxy-butyryl)-2-trichloromethyl-3- methyl-5-imino-l ,3-imidazolidinone, bromophenoxyacetyl)-2-trichloromethyl-3-(4- chlorophenyl )-4-thio-5-iminol ,3 -imidazolidinone, l benzoyl-Z-trichloromethyl-carbomethoxy-S-imino-l ,3- imidazolidinone.

The compounds of the present invention can be prepared by the reaction of an N-substituted cyanoformamide or cyanothioformamide with an N-( l,2,2,2- tetrachloroethyl)carboxamide. This reaction may be written as follows:

m-bromophenoxyethyl, I

whereinR, R and Y have the same meaning as before.

In this reaction, approximately equal molar quantities of the reactants are combined, preferably in an inert solvent. Suitable solvents are the aromatic hydrocarbons such as benzene, toluene, and xylene. The quantity of solvent used is optional, but usually an The reactionis carried out at temperatures in the range of 10 C. to 50 C., preferably at 20 C. to 30 C. The reaction is exothermic and cooling is sometimes used to limit the temperature rise. Typically, batch reactions are completed in from 1 to 10 hours at ambient temperatures. The product is usually recovered by evaporation of the solvent, followed by a water wash to remove any amine hydrochloride salt. Purification is readily accomplished by recrystallization from a suitable liquid, such as ethanol, dime'thylformamide/ethanol, isopropanol/water, and 1,2-dimethoxye'thane.

The N-substituted cyanoformamide and thioformamides used in the above reaction arereadily prepared bythe addition of hydrogen cyanide to the corresponding isocyanate or by treating isothiocyanate with an al kali metal cyanide, e.g., KCN, in aqueous ethanol followed by acidification. The reactions are as follows:

HCl

s H R-N -N MCI wherein R has the same meaning as before and M refers to an alkali metal.

Generally a slight molar excess of liquid hydrogen cyanide is added to the isocyanate dissolved in an inert.

solvent such as 1,2-dimethoxyethane. The quantity of I solvent is not critical and may range from one-half to times by weight ofthe isocyanate compound. The reaction is usually carried out in the cold; that is, temperatures below 20' C. For best results, the hydrogen cyanide is added slowly in order to control the temper-' ature. The product may be isolated by evaporating off the solvent. or preferably it may be used in the solvent without further workup.

For the reaction of the alkali metal cyanide with the isothiocyanate, KCN, is preferred. The alkali metal cyanide should be in slight molar excess. The solvent should be aqueous ethanol, the quantities not being critical and may range from one-half to 10 times by weight of the isothiocyanate compound. The reaction conditions are generally the same as those indicated above for hydrogen cyanide reacted with isocyanate. -Following formation of the intermediate-PIC] or' another acid is added to form the N-substituted thioformamide. Generally the acid will be present in an equivalent amount to that of the alkali metal cyanide.

The N-( l ,2,2,2-tetrachloroethyl)carboxamides are prepared by condensing a carboxamide with chloral, followed by reaction with thionylchloride. This reacl a s urs a Fa o The condensation reactionis carried out neat or in a solvent such as an aromatic hydrocarbon, e.g., benzene, toluene, and xylene, or a halogenated hydrocarbon, e.g., chloroform. The quantity of solvent will usually range from about one-half to 10 times by weight of the carboxamide. Essentially equal molar amounts of chloral and carboxamide are combined, preferably without a solvent at about ambient temperatures, i.e., l0-30 C. When this reaction is complete, then at least a molar amount of thionylchloride is added. This reaction is usually carried out at elevated temperatures. Under these conditions, the sulfur dioxide and hydrogen chloride by-products are volatilized from the reaction. mixture as soon as they are formed. The product, when prepared without solvent, may be used as obtained for further reaction. When prepared in a solvent it may preferably be used in that solvent without isolation, or it may be isolated by evaporation.

The present invention will be better understood by reference to the following examples of the preparation of representative compounds.

Example 1 1 l-formyl-2-trichloromethyl-3-phenyl-5-imino-l ,3- imidazolidinone N-phenylcyanoformamide, 7.3 g. (0.05 mole), and N-(1,2,2,2-tetrachloroethyl)formamide, 10.55 g. (0.05 mole), were mixed with 25 g. of benzene in a 100 ml. flask. Then 5.05 g. (0.05 mole) of triethylamine was added slowly with stirring. The temperature rose somewhat. Stirring was continued for 4 hours, and then the reaction mixture was allowed to stand for 16 hours. A precipitate was removed by filtration and washed with water to give 4.7 g. of product having a melting point of l60-3 C. Analysis for chlorine gave 36.55% (found) vs. 33.25% (calculated). An infrared spectra was consistent with the assigned structure and had strong adsorptions at 690, 830, 1050, 1220, 1475 and 1675 cm".

Example 2 1-benzoyl-2-trichloromethyl-3-methyl-4-thio-5-iminol,3-imidazolidinone N-methyl cyanothioformamide, 5.0 g. (0.05 mole), and N-(1,2,2,2-tetrachloroethyl)benzamide, 14.3 g. (0.05 mole), were mixed with 25 g. of benzene in a ml. flask. Then 5.0 g. (0.05 mole) of triethylamine was added slowly. The reaction mixture was allowed to stand 16 hours. A water soluble precipitate was removed by filtration, and the resulting filtrate was evaporated to dryness. The solid recovered in this way was recrystallized from an ethanol/water solution to give 6.0 g. of product, m.p., 122124 C. Analysis gave chlorine, 29.85%, and sulfur, 9.17% (found), vs. chlorine, 30.42%, and sulfur, 9.13% (calculated). An infrared spectra had strong adsorption at 695, 715, 810, 835, 920, 1,075, 1,450 and 1,675 cm".

Other compounds of the present invention were prepared and are tabulated in Table l.

TABLE I Cl t.

v I qvwm M V H W V w H" N Melting Point Compound Calculated Found Calculated Found M 'W C '4 W l-benzoyl-Z-trichloromethyl-3-methyl-5-imino-1,3 31.9 31.1 136-140 imidazolidinone l-benzoyl-2-trichloromethyl-3-n-butyl-5-imino-1,3- 28.3 30.3 110-118 imidazolidinone l-(2-chloroacetyl)-Z-trichloromethyI-B-phenyl:5- I -12 imino-l,3-imidazolidinone l-(Z-chloroacetyl)-2-trichloromethyl-3-methyl-5- 46.3 41.8 213-215 imino-l,3-imidazolidinone v M j" u r l-(2-chloroacetyl)-2-1richloromethyl-3-phenyl-4-thio- 8.3 8.2 Y 369 S-iminol ,3-imidazolidinone l-(2-chloroacetyl)-2-trichloromethyl-3-methyl-4-thio 9.9 10.0 44.0 41 .9 150" S-imino-l,3-imidazolidinone v 1-(2-chloroacetyl)-2-trichloromethyl-3-n-butyl-5-imino- 1 40.7 38.5 117 121 Lil-imidazolidinone 1-ace1yl*2-trichloromethyl-3-methyl-4-thio-5-imino-- 10.9 11.1 36,0 369 1 14g] 1 8 1 ,3-imidazolidinone 1 (2-chlorophenoxyacetyb-2-trichloromethyl-3- -7.7 7 .8 3 3 27 1764 79 methyl-4-thio-5-iminol ,3-imidazolidinone l-(2,4-dichlorophenoxyacetyl)-2 trichl0romethyl-3- 7.1 7.2 39.5 37.5 158-161 methyl-4-thio-5-imino-1 ,S-imidazolidinone 1-carbethoxy-Z-trichloromethyl-3-phenyl-5-imino-1,3- -1 l .f LML g V 2 .2 27.6 75-83 imidazolidinone l-carbethoxy-Z-t|ichloromethyl-3-phenyl-4-thio-5- 8.41 8.66 4

Nitrogen analysis Dccomposed UTILITY herbicides and pesticides. In general the compounds are very specific in their activity. Thus some of the compounds have activity towards fungi whereas others have high activity towards viruses, such as tobacco mosaic virus. Others have high activity towards nematodes whereas others have high activity towards herbicides. Even among those compounds which are useful as herbicides, there is a great amount of specificity. Thus some of the compounds are pre-emergenceherbicides whereas others are post-emergence herbicides. Some of the compounds are specific to broadleaved plants as opposed to the grasses.

The compounds of the present invention are herbicidal, with the exception of the compounds in which Y is Q and R is alkoxy. For pre-emergence control of undesirable vegetation these imidazolidinones will be applied in herbicidal quantitites to the environment, e.g., soil infested with seeds and/or seedlings of such vegetation. Such application will inhibit the growth of or kill the seeds, germinating seeds and seedlings. For postemergence applications the imidazolidinones of the present invention will be applied direct to the foliage or other plant parts. Some of the compounds are effective against weed grasses as well as broad-leaved weeds. Some are selective with respect to the type of application and the type of weed.

The amount of imidazolidinone administered will vary with the particular plant part or plant growth medium which is to be contacte'd, the general location of application, i.e., sheltered areas such as greenhouses as compared to exposed areas such as fields, as well as the desired type of control. For pre-emergent control of most plants dosages in the range of about 0.5 to lbs. per acre will be used. Such administration will give a concentration of about 2 to 80 ppm. urea distributed tion, such as foliar spray application, compositions con- 7 3O taining about 0.5 to 8 lbs. imidazolidinone per 100 gal.

spray will be used. Such application is equivalent to abq t 'i flo 1 S ija i1 i i1292sE t The herbicidal compositions of this invention comprise a herbicidal amount of one or more of the above described imidazolidinone intimately admixed with a biologically inert carrier. The carrier may be a liquid diluent such as water or acetone or a solid. The solid may be in the form of dust powder or granules. These 40 compositions will also usually contain adjuvants such as -a wetting or dispersing agent to facilitate their penetration into the plant growth media or plant tissue and generally enhance their effectiveness. These compositions may also contain other-pesticides, stabilizers, conditioners, fillers and the like.

Preand post-emergence herbicidal tests on representative imidazolidinones of this invention were made using the following methods:

PRE-EMERGENCE TEST cm The pot was watered and placed in a greenhouse.

The pot was watered intermittentlyand was observed for seedling emergence, health of emerging seedlings, etc. for a 3-week period. At the end of this period the herbicidal effectiveness of the imidazolidinone was representing complete kill.

POST-EMERGENCE TEST The test imidazolidinone was formulated in the same manner as described above for the pre-emergence test. The concentration of the imidazolidinone in this formulation was 5,000 ppm. This formulation was uniformly sprayed on 2 replicate pots of 24-day-old plants (approximately 15 to 2-5 plants per pot) at a dose of l mg. per cm After the plants had dried, they were placed in a greenhouse and then watered intermittently at their bases as needed. The plants were observed periodically for phytotoxic effects and physiological and morphological responses to the treatment. After 3 weeks the herbicidal effectiveness of the imidazolidinone was rated based on these observations. A 0 to 100 scale was used; 0 representing no phytotoxicity, 100 representing complete kill.

The results of these tests appear in Table II.

EXAMPLE A number of the compounds were tested for effectiveness against spores by means of a variation of The TAELE'TI Herbicidal Effectiveness Pre/Post Compound O=Wild Oats (Avena falua) W=Watergrass (Echinuchlau crusgalli) C=Crabgrass (Digitaria .ranguinalir) M=Musturd (Brarrica arvenxis) P=Pigwccd (Amaranlhus rerroflexus) L=Lamhsquarter (Chenopodium album) The compounds of the presentinvention finalise in.

the control of fungi. When used as fungicides the imidazolidinones of this invention will be formulated and applied in fungicidal amounts by conventional art methods to fungi or hosts which are subject to fungus attack, especially vegetative hosts such as plants, plant seeds, etc. The amount used will, of course, depend upon several factors such as the host, the type of fungus. the particular imidazolidinone, etc. The amount generally will range from 2 to The imidazolidinones may be combined with inert liquids or solid carriers as powders, solutions, dispersions, etc. for such use. The imidazolidinones of this invention will generally be admixed with biologically inert liquids or solids in an amount of from about 0.005 to weight percent. Hig- -her or lower amounts can be used to advantage. Preferably from 1 to 50 weight percent of the composition will be the imidazolidinones. Typical of the liquid carrier which may be admixed with the imidazolidinones of this invention include, in addition to acetone, such 60/ sop Standard Spore Slide-Germination Method for Determining Fungicital Activity, described in the American Phytopathological Society Journal, Volume 33, pages 627-632 (1943). The method is designed to measure the fungitoxic activity of fungicidal chemicals, their activity being expressed in terms of percent inhibition of germination of fungus spores. Each compound-toxicant to be tested was dissolved in acetone to a concentration of 100 ppm. These solutions were then pipetted into the wells of depression slides and allowed to dry. The wells were filled with a spore suspension of the specified test organism. A 10-fold greater volume of suspension was used than that used to apply the toxicant so that the slide concentration of toxicant was 10 ppm. The spores were then incubated in a moist chamber overnight. A group of 100 spores was examined and the number of spores germinated and not germinated was counted and recorded to show the biological activity in terms of the percent germination inhibition. Table [11 reports the results of this testing.

The nematocidal activity of several of the imidazolidinones of this invention are illustrated by the following method. 7

A 0.38 ml. portion of a 3% acetone solution of the test compound was diluted with 1 ml. acetone. The resulting solution was homogenously mixed with 20 cc. of vermiculite. The treated vermiculite was then mixed homogenously with 750 g. of soil, dry weight basis, which was severely infested with free-living nematodes (mixed culture of Meloidogyne javanica and Meloidogyne incognita). This mixing gave a concentration of approximately 15 parts of the test compound per'million parts of soil. This treated soil was stored for 4 days at 6575 F. It was then divided equally into 3 parts, each of which was put into a separate pot and kept for another 3 days. A 3-week old tomato (v. Bonny Best) seedling was then transplanted into each pot and incubated for l3'days under greenhouse conditions. After this period they were removed and the soil was washed from their roots. The nematocidal effectiveness of the test compound was determined by observing each plant for signs of nematode invasion (number of galls formed. stunting, etc.).

The results of these tests, reported as the average of the 3 replicates on a to 100 basis -0 indicating no effectiveness; 100 indicating complete effectiveness are reported in Table IV.

TABLE 111 TABLE IV Control Nematocidal Activity Compound Monolinia Alrernaria solani Compound Control I I bl/WW fmc Co a AAAA A l-benzoyLZ-trichloromethyl-3-methyl-4-thio5- 96 h] (do 00. imino-l,3imidazolidinone l fi j I 1JzeglgaygfiiEighLrgggnethyl-3-n-butyl-5-imino- 89 LS-imidazo idino'ne 1-acetyl-2-trichloromethyl-3- 100 l-(Z OhlOrOacetyQ-Z-Inchloromethyl-3-nbutylv 81 1 S-rmmo-l ,3rlmidazol1dmone imidazoli'dinone l-acetyl-Z-tn'chloromethyl-3-methyl 4-thio-5 80 imino-l,3-imidazolidinone Some of the compounds of this invention exhibit good nematocidal activity. In general those compounds wherein Y is O or S, R is alkyl, haloalkyl, aryl or halog i 3 $g i g i y aryl,R is alkyl, haloalkyl, aryl or haloaryl are preferred f no orome y n p f Immo f 2 1 imidazolidmone and l-carbethoxy-2-tr1chloromethylor nematocidal control. Further when R is aryl and R 3 hen l 3 imidazolidinone were is alkyl, it is preferred that the alkyl be at least ethyl or p y found effective in the control of tobacco mosaic Vll'US higher. Thus the lmidazolidmones of this invention may on bean leaves P used to control plant'parasitic nemtodes by expos' As will be evident to those skilled in the art, various mg them a toxlc a,moum f the lmldazohdmofle' modifications on this invention can be made or fol- Thus these lmldazohdnlones Wm normally be applied lowed, in the light of the foregoing disclosure and disto nematode'mfested 5011 at dosages i the i of 3 cussion, without departing from the spirit or scope of to 40 P acre' Theyfrlay f applied as hquld the disclosure or from the scope of the following mulations by spraying or in ection. The liquid formulaclaims tions of these imidazolidinones may be solutions, dis- 1 claim; Persions, 0r emulsimm yp Solvents which y be 1. A herbicidal composition comprising a herbicidal used are aromatics such as xylene, toluene and benu tit of the com nd of the formula zene, ketones such as cyclohexanone and the like. Y Theseliquid formulations will usually contain a wetting agent to facilitate the imidazolidinones penetration into the soil and generally enhance its effectiveness. They may also be applied as solid formulations contain- 0 ing carriers such as soil, sawdust, clay and the like. R -N N-E-R' When used as a solid, these imidazolidinones will usuy ally be plowed into the soil. Following their application to the soil, the soil will be watered to disperse the imidazolidinone below ground level. 40 wherein Y is oxygen or sulfur, R 1s lower alkyl substituted with O to 3 chlorine atoms or phenyl substituted with 0 to 2 chlorine atoms, R is'hydrogen, lower alkyl substituted with 0 to 3 chlorine atoms, phenyl substituted with 0 to 2 chlorineatoms lower alkoxy or phenoxymethyl, substituted with O to- 2 chlorine atoms on the benzene nucleus, with the proviso that when R is alkoxy Y is sulfur, admixed with a biologically inert carrier therefor.

.2. Method for controlling undesirable vegetation which comprises applying a herbicidal amount of the compound of claim 1 to said vegetation or the environment thereof.

3. The herbicidal composition of claim 1 wherein R is hydrogen, alkyl of 1 to '4 carbon atoms substituted with 0 to 3 chlorine atoms, phenyl substituted with 0 to 2 chlorine atoms, alkoxy of l to 4 carbon atoms, phenoxymethyl, substituted with O to 2 chlorine atoms on the benzene nucleus.

4. The herbicidal composition of claim 1 wherein R is alkyl of l to 4 carbon atoms or phenyl, R is hydrogen, alkyl of l to 4 carbon atoms substituted with 0 to 3 chlorine atoms, phenyl substituted with 0 to 2 chlorine atoms or phenoxymethyl substituted with 0 to 2 chlorine atoms on the benzene nucleus.

' 5. The herbicidal composition of claim 1 wherein R is alkyl of l to 4 carbon atoms or phenyL'R is hydro gen, methyl, chloromethyl, phenyl or phenoxymethyl 4 carbon atoms substituted with 0 to 3 chlorine atoms,

phenyl substituted with O to 2 chlorine atoms or phenoxymethyl substituted with 0 to 2 chlorine atoms on the benzene nucleus.

8. The method of claim 2 wherein R is alkyl of l to 4 carbon atoms or phenyl, R is hydrogen, methyl, chloromethy], phenyl or phenoxymethyl substituted with l to 2 chlorine atoms on the benzene nucleus. 

2. Method for controlling undesirable vegetation which comprises applying a herbicidal amount of the compound of claim 1 to said vegetation or the environment thereof.
 3. The herbicidal composition of claim 1 wherein R2 is hydrogen, alkyl of 1 to 4 carbon atoms substituted with 0 to 3 chlorine atoms, phenyl substituted with 0 to 2 chlorine atoms, alkoxy of 1 to 4 carbon atoms, phenoxymethyl, substituted with 0 to 2 chlorine atoms on the benzene nucleus.
 4. The herbicidal composition of claim 1 wherein R1 is alkyl of 1 to 4 carbon atoms or phenyl, R2 is hydrogen, alkyl of 1 to 4 carbon atoms substituted with 0 to 3 chlorine atoms, phenyl substituted with 0 to 2 chlorine atoms or phenoxymethyl substituted with 0 to 2 chlorine atoms on the benzene nucleus.
 5. The herbicidal composition of claim 1 wherein R1 is alkyl of 1 to 4 carbon atoms or phenyl, R2 is hydrogen, methyl, chloromethyl, phenyl or phenoxymethyl substituted with 1 to 2 chlorine atOms on the benzene nucleus.
 6. The method of claim 2 wherein R2 is hydrogen, alkyl of 1 to 4 carbon atoms substituted with 0 to 3 chlorine atoms, phenyl substituted with 0 to 2 chlorine atoms, alkoxy of 1 to 4 carbon atoms, phenoxymethyl, substituted with 0 to 2 chlorine atoms on the benzene nucleus.
 7. The method of claim 2 wherein R1 is alkyl of 1 to 4 carbon atoms or phenyl, R2 is hydrogen, alkyl of 1 to 4 carbon atoms substituted with 0 to 3 chlorine atoms, phenyl substituted with 0 to 2 chlorine atoms or phenoxymethyl substituted with 0 to 2 chlorine atoms on the benzene nucleus.
 8. The method of claim 2 wherein R1 is alkyl of 1 to 4 carbon atoms or phenyl, R2 is hydrogen, methyl, chloromethyl, phenyl or phenoxymethyl substituted with 1 to 2 chlorine atoms on the benzene nucleus. 